From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chandan Rajendra Subject: Re: constant st_ino/st_dev for non-samefs case Date: Tue, 23 May 2017 18:49:27 +0530 Message-ID: <4951608.hM2HNRSCh0@localhost.localdomain> References: Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:42746 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933347AbdEWNUP (ORCPT ); Tue, 23 May 2017 09:20:15 -0400 Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v4NDJ3xv014067 for ; Tue, 23 May 2017 09:20:09 -0400 Received: from e23smtp02.au.ibm.com (e23smtp02.au.ibm.com [202.81.31.144]) by mx0a-001b2d01.pphosted.com with ESMTP id 2amn1ntunk-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Tue, 23 May 2017 09:20:08 -0400 Received: from localhost by e23smtp02.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 23 May 2017 23:20:03 +1000 Received: from d23av04.au.ibm.com (d23av04.au.ibm.com [9.190.235.139]) by d23relay08.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v4NDJpkS4325682 for ; Tue, 23 May 2017 23:19:59 +1000 Received: from d23av04.au.ibm.com (localhost [127.0.0.1]) by d23av04.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v4NDJPiG024506 for ; Tue, 23 May 2017 23:19:25 +1000 In-Reply-To: Sender: linux-unionfs-owner@vger.kernel.org List-Id: linux-unionfs@vger.kernel.org To: Amir Goldstein Cc: Miklos Szeredi , "linux-unionfs@vger.kernel.org" On Tuesday, May 23, 2017 6:27:42 PM IST Amir Goldstein wrote: > On Wed, May 17, 2017 at 3:46 PM, Chandan Rajendra > wrote: > > On Wednesday, May 17, 2017 5:56:31 PM IST Amir Goldstein wrote: > >> On Wed, May 17, 2017 at 2:42 PM, Chandan Rajendra > > >> There is actually one task that should be very simple to do and can also > >> bring large benefit for many users. > >> > >> In his pull request for kernel 4.12 Miklos writes: > >> "The biggest part of this is making st_dev/st_ino on the overlay behave like a > >> normal filesystem ... future work will move the general case towards more sane > >> behavior." > >> https://marc.info/?l=linux-unionfs&m=149442365202823&w=2 > >> > >> The work towards constant st_dev/st_ino for the general case is not within my > >> immediate scope of interest, but it shouldn't be hard. The basic idea was > >> explained by Miklos here: > >> https://marc.info/?l=linux-unionfs&m=149259338809700&w=2 > >> > > Amir, I will work on this task. Thanks for the guidance. > > > > Hi Chandan, > > Were you able to figure out the scope of the task? > Or didn't get around to it yet? Hi Amir, I spent time understanding current overlayfs code. I am now starting to work on the problem statement. I should be able to post the patches to the mailing list by the end of this week. > > I forgot to mention that I have written tests to cover constant inode > across copy up. > If you have never used unionmount-testsuite before, now would be a good time to > start. > > You should pull my master branch from github: > https://github.com/amir73il/unionmount-testsuite > > Just do: > # cd unionmount-testsuite > # sudo ./run --ov > > It takes only ~13 sec for the basic test run to compete on my laptop. > > Then, you should remove the relaxing of constant ino check for non samefs: > https://github.com/amir73il/unionmount-testsuite/commit/958b737a0a886b6949964d51dbf8e0786ea52d02#diff-2d2badb93764e2d3fa25662025095014R496 > > And you will hit the ino check error, for example: > > # sudo ./run --ov rename-file > *** > *** ./run --ov --ts=0 rename-file > *** > TEST rename-file.py:10: Rename file and rename back > ./run --rename /mnt/a/foo100 /mnt/a/no_foo100 > /mnt/a/no_foo100: inode number wrong (got 35985, want 35584) > > > Please let me know if you intend to work on this soon, because I may be > working on some parts of this task for a different feature. > > Thanks, > Amir. > > -- chandan